package com.example.demo.config;

import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
import com.baomidou.mybatisplus.core.toolkit.PluginUtils;
import com.baomidou.mybatisplus.extension.handlers.AbstractSqlParserHandler;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.ParameterMapping;
import org.apache.ibatis.plugin.*;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.SystemMetaObject;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.type.TypeHandlerRegistry;

import java.sql.Connection;
import java.text.DateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Properties;
import java.util.regex.Matcher;

@Intercepts({@Signature(type = StatementHandler.class, method = "prepare", args = {Connection.class, Integer.class})})
@Slf4j
public class MybatisInterceptor extends AbstractSqlParserHandler implements Interceptor {

    /**
     * 封装了一下sql语句，使得结果返回完整xml路径下的sql语句节点id + sql语句
     *
     * @param configuration
     * @param boundSql
     * @param sqlId
     * @return
     */
    public static String getSql(Configuration configuration, BoundSql boundSql, String sqlId) {
        String sql = showSql(configuration, boundSql);
        StringBuilder str = new StringBuilder(100);
        str.append(sqlId);
        str.append(":");
        str.append(sql);
        return str.toString();
    }

    /**
     * 如果参数是String，则添加单引号， 如果是日期， 则转换为时间格式器并加单引号； 对参数是null和不是null的情况作了处理
     *
     * @param obj
     * @return
     */
    private static String getParameterValue(Object obj) {
        String value = null;
        if (obj instanceof String) {
            value = "'" + obj + "'";
        } else if (obj instanceof Date) {
            DateFormat formatter = DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.CHINA);
            value = "'" + formatter.format(new Date()) + "'";
        } else {
            if (obj != null) {
                value = obj.toString();
            } else {
                value = "";
            }

        }
        return value;
    }

    /**
     * 进行？的替换
     *
     * @param configuration
     * @param boundSql
     * @return
     */
    public static String showSql(Configuration configuration, BoundSql boundSql) {
        // 获取参数
        Object parameterObject = boundSql.getParameterObject();
        List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
        // sql语句中多个空格都用一个空格代替
        String sql = boundSql.getSql().replaceAll("[\\s]+", " ");
        if (CollectionUtils.isNotEmpty(parameterMappings) && parameterObject != null) {
            // 获取类型处理器注册器，类型处理器的功能是进行java类型和数据库类型的转换
            // 如果根据parameterObject.getClass(）可以找到对应的类型，则替换
            TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();

            if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
                sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(parameterObject)));

            } else {
                // MetaObject主要是封装了originalObject对象，提供了get和set的方法用于获取和设置originalObject的属性值,
                // 主要支持对JavaBean、Collection、Map三种类型对象的操作
                MetaObject metaObject = configuration.newMetaObject(parameterObject);
                for (ParameterMapping parameterMapping : parameterMappings) {
                    String propertyName = parameterMapping.getProperty();
                    if (metaObject.hasGetter(propertyName)) {
                        Object obj = metaObject.getValue(propertyName);
                        sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(obj)));
                    } else if (boundSql.hasAdditionalParameter(propertyName)) {
                        // 该分支是动态sql
                        Object obj = boundSql.getAdditionalParameter(propertyName);
                        sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(obj)));
                    } else {
                        // 打印出缺失，提醒该参数缺失并防止错位
                        sql = sql.replaceFirst("\\?", "缺失");
                    }
                }
            }
        }
        return sql;
    }

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        try {
            // 获取xml中的一个select/update/insert/delete节点，主要描述的是一条SQL语句
            Object parameter = null;
            // 获取参数，if语句成立，表示sql语句有参数，参数格式是map形式
            if (invocation.getArgs().length > 1) {
                parameter = invocation.getArgs()[1];
                System.out.println("parameter = " + parameter);
            }

            StatementHandler statementHandler = PluginUtils.realTarget(invocation.getTarget());

            MetaObject metaObject = SystemMetaObject.forObject(statementHandler);
            MappedStatement mappedStatement = (MappedStatement)metaObject.getValue("delegate.mappedStatement");
            // 获取到节点的id,即sql语句的id
            String sqlId = mappedStatement.getId();
            log.info("sqlId = " + sqlId);
            this.sqlParser(metaObject);
            // BoundSql就是封装myBatis最终产生的sql类
            BoundSql boundSql = (BoundSql)metaObject.getValue("delegate.boundSql");
            // 获取节点的配置
            Configuration configuration = mappedStatement.getConfiguration();
            // 获取到最终的sql语句
            String sql = getSql(configuration, boundSql, sqlId);
            log.info("sql = " + sql);
        } catch (Exception e) {
            log.info(e.getMessage(), e);
        }
        // 执行完上面的任务后，不改变原有的sql执行过程
        return invocation.proceed();
    }

    @Override
    public Object plugin(Object target) {
        return Plugin.wrap(target, this);
    }

    @Override
    public void setProperties(Properties properties) {

    }
}
